This invention relates to safety-arming devices for rocket motors wherein an electro-initiator device (EID) is used to ignite a booster charge of pyrotechnic material which in turn ignites the rocket propellant. More particularly, this invention relates to such devices which will prevent rocket motor ignition by containing premature EID combustion, and which utilize energy from the properly ignited EID to remove an ignition barrier between the EID and the booster charge.
Rocket motors of the type used in guided missiles which are launched from surface or airborne platforms use a variety of devices for preventing unintentional rocket motor ignition. One class of such devices uses an EID aligned with a booster charge in the rocket motor and rendered safe by electric switches, electronic filters, electrically insensitive bridgewires or by a combination of such elements. Another class of similar devices utilizes a barrier between the EID and the booster charge. When rocket motor ignition is likely to be desired, the barrier is removed manually by external means.
These designs are not sufficiently fail-safe to be stored in quantity in the assembled condition and thus must have the EID installed just prior to use. Also it is possible for inexperienced personnel to improperly arm the rockets thereby making them impossible to launch, or to unintentionally store rockets in the armed condition with other unarmed rockets and thus create an unreasonable danger of explosion. Further, freedom of missile design is somewhat restricted if a provision must be made for installation of an EID prior to use. The missile must have an access port for EID installation and therefore will result in a more complex structure than if the EID is permanently installed deep within the missile.